cxl: Force psl data-cache flush during device shutdown

This change adds a force psl data cache flush during device shutdown
callback. This should reduce a possibility of psl holding a dirty
cache line while the CAPP is being reinitialized, which may result in
a UE [load/store] machine check error.

Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/pci.c

@@ -1610,6 +1610,9 @@ static void cxl_pci_remove_adapter(struct cxl *adapter)
 	cxl_sysfs_adapter_remove(adapter);
 	cxl_debugfs_adapter_remove(adapter);
 
+	/* Flush adapter datacache as its about to be removed */
+	cxl_data_cache_flush(adapter);
+
 	cxl_deconfigure_adapter(adapter);
 
 	device_unregister(&adapter->dev);